185 AFR heads on 302

Rick 91GT · Sep 28, 2005

Yes you will have to notch the pistons to clear the large valve.

xarnyz · Sep 28, 2005

Thanks man
Whoever told me these 302's were way easier to work on than the gsx I had was lying.

Lyncher · Sep 28, 2005

^^^ Try working on an ls1...

ifucan · Sep 28, 2005

ive done this...i used 1.6 rr and a stock cam...let me be emphatic...NO BOTTOM END, car would pull like crazy from 3500 up but didn't have any guts down low=bad short times, i can best equate it to a two stroke dirtbike...obviously like rick said, it ain't worth it w/o the supporting hardware...reason i did it was because i bought them for a 351w and just wanted to 'play' w/them on the smaller displacement engine till i got my new bullet done...in the end tho, i took them off for some p heads and im much happier...p heads have tq all over the afr's and still pull respectable up top(because they are a better match for my combo)...good luck...o and no flycutting here

xarnyz · Sep 28, 2005

ifucan said:
ive done this...i used 1.6 rr and a stock cam...let me be emphatic...NO BOTTOM END, car would pull like crazy from 3500 up but didn't have any guts down low=bad short times, i can best equate it to a two stroke dirtbike...obviously like rick said, it ain't worth it w/o the supporting hardware...reason i did it was because i bought them for a 351w and just wanted to 'play' w/them on the smaller displacement engine till i got my new bullet done...in the end tho, i took them off for some p heads and im much happier...p heads have tq all over the afr's and still pull respectable up top(because they are a better match for my combo)...good luck...o and no flycutting here

Sorry, but what's flycutting? Anyhow, you did this without re-notching your pistons? Were they stock pistons?

Rick 91GT · Sep 28, 2005

He used a stock cam, if he would have floated the valves it would have hit on the outside edges of the eyebrows/valve reliefs.

Personally a stock cam has no place with a head like that, you are wasting a ton of power. I understand why he did it since he was building something else.

Flycutting is notching

lickem · Sep 28, 2005

ive got a stock 91 lx with a 302 and got a good deal on some 1.7 roller rockers and thought about putting them on to get alittle more fun out of it, am i going to have clearance problems by installing them? im not sure if i have the dish hyper's or the flat tops.

also a question on the afr 185's and 165's what is everyones thoughts on a supercharger application, still go with the 165's?

thanks

ifucan · Sep 28, 2005

stock 120k shortblock no flycutting

ImportEater98 · Oct 5, 2005

To cut or not to cut.....thats my question!

I'm still unclear on this, so forgive me if this has been answered...but...I am building up a 306. It has Keith Black Flat Top hypers in it. I would like to run an AFR 185. I know from previous searching that the 2.02 valve will infact hit a stock piston...do these aftermarket slugs have more of a relief in them to accomidate the bigger valve? I really don't want to flycut these pistons...i think it makes them weaker...they are as thick as they are for a reason IMO.
I would like to run the Comp Cams XE282HR cam 565/574 lift, 232/240 @0.50"
The AFR sight claims with 10.1:1 (I have about 9.6) this combo is capable of 455 fwhp......please steer me in the right direction!

Grn92LX · Oct 5, 2005

A good aftermarket slug will have a deeper relief. Try calling kieth black and asking them. If you have the clearance, thats a great head for your 306.

87'GTstang · Oct 5, 2005

The best bet for large valves (with the exception of the TFS heads) such as 2.02" and greater is that it is best to install heads of this nature during a rebuild. No point in spending the money at a machine shop to flycut the factory pistons when you will be having to buy new pistons (possibly again) for a rebuild anyway. The valve reliefs on the stock pistons simply are not large enough. We are talking about going from a stock 1.78" intake valve to a 2.02" valve size - don't see a problem? Only other ways around it are makeing sure the came is very carefully selected or lowering compression by increasing PTV clearances.

As with the AFR 165 vs. 185 heads, for smaller engines and/or low-revving engines the 165's are better because they have a better port velocity than their bigger cousin. As always with engines, things must be matched well for things to work well and port velocity must match power and RPM demands and needs or else the combination doesn't end up working its best.

rd · Oct 5, 2005

To state it clearly, when I clayed my GT40s with my TRW forged flat tops (L2482F)with valve reliefs, the closest approach was at the edge of the valve, much closer than I expected. I had plenty of vertical clearance. This was with the 1.84 intakes, etc.

Just install a head and check it to be sure.

5spd GT · Oct 5, 2005

Depends on what kind of piston you have whether it will have a deeper relief or not. No matter if it is good or bad. Quality or not.

ImportEater - Don't expect 455fwhp with accessories and tranny attached

Hissing Cobra · Oct 5, 2005

ImportEater98 said:
I'm still unclear on this, so forgive me if this has been answered...but...I am building up a 306. It has Keith Black Flat Top hypers in it. I would like to run an AFR 185. I know from previous searching that the 2.02 valve will infact hit a stock piston...do these aftermarket slugs have more of a relief in them to accomidate the bigger valve? I really don't want to flycut these pistons...i think it makes them weaker...they are as thick as they are for a reason IMO.
I would like to run the Comp Cams XE282HR cam 565/574 lift, 232/240 @0.50"
The AFR sight claims with 10.1:1 (I have about 9.6) this combo is capable of 455 fwhp......please steer me in the right direction!

John, I got your e-mail and for some reason, I can't send outgoing mail. Therefore, I'll reply here.

Your combo sounds almost exactly like mine. As you know, I too, have a 306 with the Keith Black hyperutectic pistons. Their notches must be deep enough because I have the AFR 185's (58 cc's) and they fit without a problem. Also, my block was decked to create 10:8:1 compression. Definitely check with my brother (Retro 5.0 or Rick91GT) as they know their stuff about measurements.

As for the cam, I'm not too sure how big you can go. I've got an Elgin Pro Stock cam in mine (248 INT/258 EXH @ .50, .536 INT/.560 EXH) and it runs great on the street and on the track (12.42 @ 109) on 93 octane.

I do not believe that you'll get 455 flywheel horsepower but I could be wrong. Mine made 307 at the wheels, which would be somewhere in the 360-370 flywheel horsepower range. Of course, I may also be costing myself some horsepower because of my twin four barrel setup.

Good luck!

Topdowncruise · Oct 6, 2005

lickem said:
ive got a stock 91 lx with a 302 and got a good deal on some 1.7 roller rockers and thought about putting them on to get alittle more fun out of it, am i going to have clearance problems by installing them? im not sure if i have the dish hyper's or the flat tops.

also a question on the afr 185's and 165's what is everyones thoughts on a supercharger application, still go with the 165's?

thanks

No clearance problems with my setup with the stock cam.

ImportEater98 · Oct 6, 2005

Hissing Cobra said:
John, I got your e-mail and for some reason, I can't send outgoing mail. Therefore, I'll reply here.

Your combo sounds almost exactly like mine. As you know, I too, have a 306 with the Keith Black hyperutectic pistons. Their notches must be deep enough because I have the AFR 185's (58 cc's) and they fit without a problem. Also, my block was decked to create 10:8:1 compression. Definitely check with my brother (Retro 5.0 or Rick91GT) as they know their stuff about measurements.

As for the cam, I'm not too sure how big you can go. I've got an Elgin Pro Stock cam in mine (248 INT/258 EXH @ .50, .536 INT/.560 EXH) and it runs great on the street and on the track (12.42 @ 109) on 93 octane.

I do not believe that you'll get 455 flywheel horsepower but I could be wrong. Mine made 307 at the wheels, which would be somewhere in the 360-370 flywheel horsepower range. Of course, I may also be costing myself some horsepower because of my twin four barrel setup.

Good luck!

Thanks for the comforting info Pete...this takes a lot of my guesswork out!
Take Care!
John

aleborjas · Oct 6, 2005

i have a 306 and i am buying a pair of 185's with RPMII intake its little big but im planing on a stroker in future!

185 AFR heads on 302

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